Diffuse Phase Transition and Phase Separation in Cr-DopedNd1/2Ca1/2MnO3: A Relaxor Ferromagnet

Abstract
We have investigated the diffuse phase transition accompanying the formation of submicrometric ferromagnetic-metallic (FM) domains embedded in the antiferromagnetic charge-ordered state in Nd1/2Ca1/2MnO3 crystals, which is caused by quenched random field originating from Cr impurities substituted on the Mn sites. The fraction of the FM phase volume or the size of the FM cluster can be controlled to a large extent by the magnetic-field annealing as well as the Cr content. The observed phenomena are reminiscent of those of relaxor ferroelectrics composed of ferroelectric clusters embedded in paraelectric matrix.